Assembly of a receiver and a sensor

ABSTRACT

An assembly of at least one radiation detector, at least one radiation emitter and a housing configured to be positioned inside the ear canal of a person or animal, the detector(s) and emitter(s) being provided in or on the housing, the emitter(s) being configured to emit radiation away from the housing and the detector(s) being configured to receive radiation directed toward the housing. No overlap may be provided between the field of view of the radiation detector(s) and the emitter(s), such as by providing a blocking element.

The present invention relates to a housing comprising a sensorcomprising one or more radiation emitters and one or more detectors. Thehousing may be configured to be positioned in an ear canal of a personwhere the sensor may be a so-called PPG sensor.

Technology of this type may be seen in U.S. Pat. No. 8,700,111,US2018/0042554, U.S. Pat. No. 9,794,653, U.S. Ser. No. 10/219,069, U.S.Ser. No. 10/003,882, U.S. Pat. No. 7,747,032, US2015237429, U.S. Pat.No. 7,995,782, EP3073765, U.S. Pat. Nos. 9,106,999 and 9,654,854.

In a first aspect, the invention relates to an assembly of at least oneradiation detector, at least one radiation emitter and a housingconfigured to be positioned inside the ear canal of a person or animal,the detector(s) and emitter(s) being provided in or on the housing, theemitter(s) being configured to emit radiation away from the housing andthe detector(s) being configured to receive radiation directed towardthe housing.

Preferably, the detector(s) and emitter(s) form a sensor system.

In this context, an assembly of a sensor and a housing may, in additionto the sensor and housing, comprise also other elements such asreceiver(s), amplifier(s), processor(s), battery, optical components,electrical connections (e.g. (flex)pcb), other transducers (actuators,sensors) or the like. The sensor and housing may be attached to eachother or not. In one situation, the sensor is provided inside thehousing.

Also, the present assembly is especially suited for positioning in theear canal of a person where sensors may be used for a number ofpurposes. One purpose is to determine the pulse or other physiologicalsigns of a person like blood pressure, heart rate variability orrespiration rate, such as using the so-called PPG (photoplethysmography)which relates to absorption, reflection and/or scattering of radiationin the tissue, including blood vessels. On the basis of the radiationreceived, the pulse or other physiological parameters of the person maybe determined, as the absorption, reflection and/or scattering in thetissue will vary with the perfusion of the tissue andexpansion/contraction of the blood vessels. Thus, the variation ofreceived radiation will correspond to the physiological parameters ofthe person like pulse frequency, blood pressure etc.

As the absorption, reflection and/or scattering of radiation in thetissue also depends on other tissue parameters than perfusion, PPG canalso be used to determine other biological parameters like changes inoxygenation of the blood.

The emitter(s) is/are configured or positioned to emit radiation awayfrom the housing. Clearly, an emitter may emit radiation within a fan orcone (of any cross sectional shape) or another light distributionpattern, where some of the radiation may be emitted toward or along thehousing but where at least some of the radiation is emitted in adirection away from the housing. An emission cone may be defined bydirections from the emitter toward the surroundings where a particularoutput intensity or intensity portion, such as half the maximumintensity output in a direction from the emitter, is seen. In onesituation, the emission cone may be defined as the FWHM (full width halfmaximum; see below) of the emitter, i.e. the cone inside of which theintensity per area is higher than half the maximum intensity per area.In that situation, the cone is defined where half the maximum intensityis output per area. Clearly, the cone may be defined by any percentageof the maximum intensity output per area.

The detector(s) is/are also configured to or positioned to receiveradiation directed toward the housing. The detector(s) may have a fieldof view which may also be defined as a cone or other shape, where thefield of view can be defined as the set of angles (or the 3D shape)inside which the detection efficiency is higher than half the maximumdetection efficiency of the detector. Also in this situation may thefield of view be defined by any percentage of the maximum sensitivity.

The housing is configured to be positioned inside an ear canal of aperson. In this situation, the housing preferably has a volume notexceeding 1000 mm³, such as not exceeding 500 or even 250 mm³. Thehousing may be oblong and have a longitudinal axis. The length along thelongitudinal axis may be 15 mm or less, such as 11 mm or less. In aplane perpendicular to the longitudinal axis, the housing may have anarea not exceeding 64 mm², such as not exceeding 30 mm² and/or have alongest dimension not exceeding 15 mm, such as not exceeding 12 mm, 9 mmor 7 mm.

As mentioned, the sensor may now be an optical sensor which may be usedfor e.g. determining a pulse or other physiological signs of a personusing the so-called PPG technique. This sensor has at least a radiationemitter and a radiation detector. Clearly, the radiation may be selectedaccording to a desired measurement or detection. The PPG techniquerelates to absorption, scattering and/or reflection of the tissue as, incase of the detection of e.g. blood pressure or heartrate), a functionof the perfusion of the tissue caused by the action of the heart. Otherparameters may be determined from radiation absorption or the like.Thus, the wavelength of the radiation may be selected for the particularpurpose.

Then, the radiation emitter of course will also be selected depending onthe purpose. Radiation emitters may emit a broad spectrum of radiation,a more narrow spectrum, or only one or two wavelengths as desired. LEDs,laser diodes and the like may be used. Of course, optical fibres,filters, gratings, mirrors, lenses, windows and the like may be providedfor guiding and adapting the radiation, such as if the outputcharacteristics, such as the output cone size/angle of the actualradiation emitter is not as desired.

Optical filters can be used to minimize detection of unwanted signals,like the radiation from external light sources (e.g. sunlight).

The detector also will be selected based on the purpose and theradiation wavelength. Also, some detector types are faster reacting thanothers and some types are able to detect lower intensities than others.Again, lenses and the like may be used for adapting the field of view,if desired, or for collecting radiation and guiding it to the detector.

In one embodiment, the method comprises connecting the emitter(s) anddetector(s) to the housing. In this manner, handling of the assembly iseasier, and relative positioning and directing of the detectors andemitters—and the housing, is made easy.

Often, a receiver is present in the assembly housing. The receiver is asound generator so that the housing forms a hearing device or part of ahearing device. In one embodiment, the assembly forms an RIC (ReceiverIn Canal), mounted in the ear canal by means of e.g. a dome or (custom)mould for generating sound to the inner ear. Other embodiments might bethe ITE (In The Ear) hearing instrument or earbud. This RIC, ITE, earbudor alike may then have the additional function provided by the sensor.

In one embodiment, one or more of the detector(s) and/or one or more ofthe emitter(s) is/are configured to be directed at least substantiallyin a vertical direction, such as when positioned in an ear canal of aperson in an upright position looking and straight ahead or when theperson is in any other position.

Clearly, all aspects, embodiments and situations of the invention may becombined in any manner. Any number of aspects/embodiments/situations maybe combined.

In this connection, the vertical direction may be within 45 degrees ofvertical, such as within 30, 25, 20, 15, 10 or 5 degrees from vertical(such as a vector or direction of gravity).

Preferably, the direction is downwardly directed.

It may be preferred that the housing engages the ear canal at this(vertical) position so that there is no distance and/or a reduced lossof radiation between the emitter/detector and the ear canal tissue.

Often, a person's ear canal is more or less oval in cross section wherethe longest axis or dimension is upwardly/downwardly directed.Naturally, the shape need not be completely oval, but may be easilyfitted to an oval shape. Then, this one or more detector(s) and/oremitter(s) may be directed along the major axis of this ovality or alongest cross sectional dimension of the ear canal cross section.

In one embodiment, the method comprises the step of positioning theassembly in the ear canal of a person so that one or more of thedetector(s) and/or one or more of the emitter(s) is/are directed atleast substantially in a vertical direction.

As mentioned, this direction may be a downward direction and/or along alargest dimension of an oval cross section of the ear canal.

For some types of sensing, such as when based on absorption, it isdesired to have an overlap in the field(s) of view of the detector(s)and the emission cone(s) of the emitter(s). For other types of sensingthis is not that important, such as when the determination is based onreflection/scattering where radiation may be scattered from an emissioncone to a field of view.

In some types of sensing, it is desired that if the fields of view ofthe detector(s) and the cone(s) of the emitter(s) overlap, this overlapis positioned farther away from the detector/emitter than apredetermined distance. This may be the situation in PPG measurements asit is desired that the radiation detected has traveled a minimumdistance in the tissue before detection. This may be achieved by eitherpositioning the emitter/detector far from each other and/or by directingthem in different directions, for example.

In one embodiment:

-   -   one of the radiation detectors is positioned in or at the        housing and has a field of view defining a view axis,    -   one of the radiation emitters is positioned in or at the housing        and has an emission cone defining an emission axis.

Naturally, a field of view and/or emission cone may be defined by theemitter/detector itself and/or optics or other elements positioned inthe path of the radiation. A lens will often change the path of theradiation and thus the field of view or the cone.

It may be desired to provide the detector(s) and/or emitter(s) in or atthe housing wall in order to allow transport of the radiation to/fromthe surroundings of the housing. Alternatively or additionally, one ormore windows transparent to the radiation may be provided in the housingto allow radiation from the emitter to exit the assembly housing and/orradiation from outside of the assembly housing to reach the detector.

Naturally, the detector will define an angle or field of view withinwhich it is able to successfully receive or detect radiation. This anglewill have a central view axis which usually is a symmetry axis of thedetector. Naturally, a mirror, lens or the like may be provided in frontof the detector so that the axis is instead defined by this mirror/lens.The light-guiding to change angle at which light exits/enters the RICmay be seen in U.S. provisional application No. 62/733,327.

The same is the case for the emitter which will emit the radiationwithin a cone, typically, which again will have a central emission axisagain typically being a symmetry axis of the emitter, for exampleperpendicularly to an emitting surface of the emitter. Also here, a lensor the like may be provided in front of the emitter so that the outputcone is defined by this lens instead.

In one situation, there is no overlap between the field of view and theemission cone. In this situation, the radiation needs to be scattered orreflected at least once (if it is not absorbed and other radiation, suchas radiation emitted by the tissue is detected).

Naturally, the emitter(s) and detector(s) need not be provided at/in thesame side of the housing or on different sides thereof. Due to radiationbeing reflected/scattered, the radiation may still travel from theemitter to the detector even when it has to travel around the housing oraround a corner thereof.

In one situation, no overlap exists between the field of view and theemission cone within a distance of 0 or 1 mm from the housing, such aswithin a distance of 2, 3, 4, 5 or 6 mm from the housing. In thismanner, it may be imposed on the radiation that it needs to travel aminimum distance within the tissue.

A distance between an emitter or detector and a surface of a tissue ofear canal may vary between 0 mm (e.g. in case of a custom mold type ofhearing device, e.g. ITE, a RIC with a custom dome, or e.g. in case atsome portions of ear canal a RIC touches the surface of ear canal), orup to 6-15 mm depending on a size of a person's ear canal.

In one situation, the housing comprises at least a first and a secondnon-overlapping surface parts directed in different directions, where:

the view axis of one of the detector(s) extends at an angle, such as anangle in the interval of 30-160 degrees, such as within the interval of45-135 degrees, such as around 90 degrees, to the first surface part andthe emission axis of one of the emitter(s) extends at an angle, such asan angle in the interval of 30-160 degrees, such as within the intervalof 30-160 degrees, such as within the interval of 45-135, such as around90 degrees to the second surface part.

The two surface parts may have general directions (such as a normalvector to the surface part) with an angle between them, such as an anglein the interval of 30-160 degrees, such as within the interval of 45-135degrees, such as around 90 degrees.

In this situation, positioning the emitter at or in one wall, such aswhen emitting radiation along a central axis perpendicular to that wall,positioning the receiver on or at an adjacent wall with a central axisperpendicular to that wall, the axes of the receiver and emitter will beperpendicular to each other.

In one situation, a minimum distance of 2 mm, such as 3 mm, such as 4mm, such as 5 mm, such as at least 6 mm exists between an emitter and adetector. This distance usually is along the outer surface of thehousing and from a centre of the detector to a centre of the emitter.The distance may be along a straight wall portion or along a bent outersurface, such as over an edge or corner. The distance may be theshortest distance between the emitter and the detector.

In another embodiment, a detector and an emitter are provided in or atthe same side surface, where an angle of no less than 5 degrees, such asat least 10 degrees exists between the view angle and emission angle.Preferably, the view angle and emission angle point away from eachother. In this situation, there may or may not be an overlap between thefield of view and the cone, depending on the width of the field of viewand cone around the respective axis.

In situations where e.g. a minimum distance between emitter and detectoris not possible or realistic due to the housing or surface being verysmall, this relative angling may ensure that the overlap is not presentor is present only sufficiently far from the housing.

In one embodiment, the housing has 6 surface portions, pairwise at leastsubstantially parallel, where each pair of surface portions are at leastsubstantially perpendicular to the other pairs of surface portions, thefirst surface portion being one of the 6 surface portions.

The housing may have rounded corners and edges. Detector(s) and/oremitters may also be provided on or at edges or corners.

In one embodiment, the second surface portion extends between at leasttwo of the 6 surface portions and has a non-zero angle to each of the atleast two of the 6 surface portions.

In one embodiment of the method:

-   -   one of the radiation detectors detects radiation within a field        of view defining a view axis,    -   one of the radiation emitters emits radiation within an emission        cone defining an emission axis.

Then, there may be no overlap between the field of view and the emissioncone.

Alternatively, no overlap may exist between the field of view and theemission cone within a distance of 1 mm from the housing.

The housing may comprise at least a first and a second non-overlappingsurface parts directed in different directions, where:

-   -   the view axis of one of the detector(s) extends at an angle,        such as an angle in the interval of 30-160 degrees, such as        within the interval of 45-135 degrees, such as around 90        degrees, to the first surface part and    -   the emission axis of one of the emitter(s) extends at an angle,        such as an angle in the interval of 30-160 degrees, such as        within the interval of 30-160 degrees, such as within the        interval of 45-135, such as around 90 degrees to the second        surface part.

One aspect of the invention relates to an assembly of a receiver, aradiation emitter, a radiation detector and an assembly housing,wherein:

-   -   the receiver has a receiver housing and is positioned inside the        assembly housing,    -   the radiation detector is positioned in the assembly housing and        has a reception direction or view axis along a first direction,    -   the radiation emitter is positioned in the assembly housing and        has an emission direction or axis along a second direction, an        angle existing between the first and second directions,    -   one or more windows transparent to the radiation are provided in        the assembly housing for allowing radiation from the emitter to        exit the assembly housing and radiation from outside of the        assembly housing to reach the detector.

Then, the assembly housing may be arranged to have the radiation emitteror radiation detector positioned in ear canal to allow radiation to exittowards or enter from the direction towards the bottom of the ear canal.

In one situation:

-   -   one of the radiation detectors is positioned in the housing and        has a field of view, and    -   one of the radiation emitters is positioned in the housing and        has an emission cone,

where a (minimum) distance of at least 1 mm, such as at least 2 mm, suchas at least 3 mm, such as at least 4 mm, such as at least 5 mm, such asat least 6 mm, such as at least 7 mm, such as at least 8 mm existsbetween the field of view and the cone, within a distance of at least 1mm, such as at least 2 mm, such as at least 3 mm from the housing.

This may be in order to have the received intensity sufficiently low tonot overpower the detector or in order to have a sufficient overlap ortravelling distance in the tissue to arrive at a sufficient interactionwith the tissue to be able to discern the parameter sought for. This maybe achieved by positioning the detector and emitter so that there is noor minimal overlap in their field of view and the cone within a certaindistance from the emitter/detector. This may be achieved by providing adistance between the emitter and detector or by angling these away fromeach other.

Requiring a minimum distance will ensure that a desired minimumproportion of the radiation interacts with the tissue until reaching thedetector. Also, radiation reaching the detector after having traveled atoo small distance in the tissue, might contain too little useful signalsuch that the signal level (radiation modulation by biologicalparameters like perfusion) is too low compared to the (inherent) systemnoise, yielding a too low signal-noise ratio (SNR).

In one situation, the housing is configured to engage an ear canal at aposition comprised within the field of view or the cone. In thissituation, a good interface may be obtained for guiding the radiationinto the tissue. Also, when the tissue engages the housing at thisposition, a good control is obtained of how far the radiation travelsthrough the tissue.

In one situation, the field of view and/or cone is defined by a windowand/or a lens at the outer surface of the housing. In that situation,even a displacement between the emitter/detector and the housing may behandled by the action of the window/lens.

In one embodiment of the method:

-   -   one of the radiation detectors receives radiation within a field        of view,    -   one of the radiation emitters emits radiation within an emission        cone,

where a (minimum) distance of at least 1 mm, such as at least 2 mm, suchas at least 3 mm, such as at least 4 mm, such as at least 5 mm, such asat least 6 mm, such as at least 7 mm, such as at least 8 mm existsbetween the field of view and the cone, within a distance of at least 1mm, such as at least 2 mm, such as at least 3 mm from the housing.

Then, the housing may engage an ear canal at a position comprised withinthe field of view or the cone.

Also, the field of view and/or cone may be defined by a window and/or alens at the outer surface of the housing.

In one embodiment, the assembly further comprises a receiver having areceiver housing, wherein at least one of the one or more detectors andone or more emitters is attached to the receiver housing.

A receiver is a sound generator and may be based on any desiredtechnology, such as moving magnet, moving coil, balanced armature,electret technology, MEMS technology, piezo technology or the like. Thereceiver is preferably configured to receive a signal, such as anelectrical signal, and output sound or vibration with correspondingfrequency contents, at least within a desired frequency interval.

Preferably, the receiver is a miniature receiver, such as a soundgenerator with a largest dimension of no more than 10 mm, such as nomore than 8 mm, such as no more than 6 mm or no more than 5 mm. In onesituation, the sound generator housing may have a volume of no more than100 mm³, such as no more than 70 mm³, such as no more than 50 mm³, suchas no more than 30 mm³. Miniature sound generators may be used inhearing aids, hearables or personal hearing devices, such as ear phonesor the like.

The receiver often has a diaphragm defining, with an inner surface ofthe receiver housing, the first chamber in the receiver housing. Often,another chamber is defined at least partly by the other side of thediaphragm and the inner surface of the housing. The sound output oftenextends from inside of the receiver housing and to the outside thereof,such as from the first and/or other chamber, so that sound generated bythe diaphragm may escape the receiver housing via the sound output.

The sound output is provided in a housing wall part of the receiverhousing, typically a flat or plane wall part of the receiver housing.

Usually, a diaphragm is flat or plane or at least extends in a plane,which is defined as the first plane. The diaphragm may be curved or haveindentations or ridges, so that the first plane may be a symmetry plane,a lower plane, an upper plane, a plane in which the diaphragm issupported, such as at its edges, or the like.

In one embodiment, the assembly comprises also additional parts, such asa spout, a dome, a sound channel or the like, where the assemblyaccording to the first aspect is attached to the sound channel, dome,spout or the receiver housing, an where one of the emitter and detectoris provided in/at the outer housing and/or receiver housing as describedin relation to the first aspect and where the second of the emitter anddetector is attached to another portion of the outer assembly, such asthe outer device housing, dome, sound channel, spout or the like.

Domes may be used for keeping the housing in the desired position.Single domes, double domes, custom domes, custom moulds may be provided.An alternative it the so-called sportslock.

In one situation, the assembly further comprises a first window or lensin the receiver housing and a second window or lens in either thehousing or an element, such as a dome or spout, attached to the housing,wherein an emitter is positioned so as to emit radiation toward one ofthe first and second window/lens and a detector is positioned so as toreceive radiation via another of the first and second window/lens.

It may be desired to have one or more detector(s) directed in aparticular direction, such as downwardly, and have a number of emitterspositioned distributed over the assembly to emit radiation in differentdirections. Then, it may be desired to have the detector in the outerhousing, as the orientation of this may be determined vis-à-vis an earcanal, and at least some of the emitters in or on other elements, suchas the receiver, spout or dome.

One aspect of the invention relates to an assembly comprising a sensorand a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   the sensor comprises a radiation emitter and a radiation        detector,    -   the receiver housing and at least one of the emitter and the        detector overlap at least partly when projected on to a first        plane, and    -   the receiver housing and the at least one of the emitter and the        detector overlap at least partly when projected on to a second        plane perpendicular to the first plane.

Then, the assembly may further comprise an additional element, such as aspout or dome, attached directly or indirectly to the receiver, one ofthe emitter and the detector being attached to the additional element.

In one example:

the detector has a field of view having a first central axis,

-   -   the emitter defines an emission cone having a second central        axis, where a non-zero angle exists between the first and second        central axes.

The non-zero angle may be 1-5 degrees, 5-10 degrees, 7-20 degrees, 5-50degrees, 10-80 degrees or the like. The axes may point toward each otheror away from each other.

In one situation, the receiver housing has a number of at leastsubstantially plane surface parts, wherein the detector is provided inor at a first of the surface parts and the emitter is provided in or ata second of the surface parts. Alternatively, at least one of thedetectors/emitters may be positioned in or at an edge or corner thereof.

In one embodiment of the method, the method may further comprise areceiver having a receiver housing, wherein at least one of the one ormore detectors and one or more emitters is attached to the receiverhousing.

Then, an emitter may be positioned so as to emit radiation toward one ofa first and a second window/lens and a detector is positioned so as toreceive radiation via another of the first and second window/lens, thefirst window or lens being provided in or at the receiver housing andthe second window or lens being positioned in or at either the housingor an element attached to the housing,

An aspect of the invention relates to a method of providing an assemblycomprising a sensor and a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,            and    -   the sensor comprises a radiation emitter and a radiation        detector,    -   the method comprising providing the receiver and the sensor so        that:    -   the receiver housing and at least one of the emitter and the        detector overlap at least partly when projected on to a first        plane, and    -   the receiver housing and the at least one of the emitter and the        detector overlap at least partly when projected on to a second        plane perpendicular to the first plane.

The method then may further comprise an additional element attached tothe receiver, one of the emitter and the detector being attached to theadditional element.

Then:

-   -   the detector may receive radiation in a field of view having a        first central axis,    -   the emitter may output radiation in an emission cone having a        second central axis, where a non-zero angle exists between the        first and second central axes.

Also, the receiver housing may have a number of at least substantiallyplane surface parts, wherein the detector is provided in or at a firstof the surface parts and the emitter is provided in or at a second ofthe surface parts.

In one situation, it may be desired to position the emitter(s) anddetector(s) in a particular manner, where radiation may travel from theemitter to the detector through a too short path and thus createproblems. Often, the problems are created by an overlap being providedbetween the field of view and the cone and being positioned in anundesired position, such as too close to the detector. In thatsituation, it may be desired to provide a radiation blocking elementpreventing this radiation.

Thus:

-   -   one of the radiation detectors is positioned in the housing and        has a field of view,    -   one of the radiation emitters is positioned in the housing and        has an emission cone,

the assembly further comprising a radiation blocking element provided inan overlap between the field of view and the cone.

A radiating blocking element may be positioned in an overlap between thefield of view and the cone. Usually, the blocked overlap is a portion ofthe overlap which is close or the closest to the housing, the detectorand/or the emitter. In that manner, radiation is prevented fromtravelling through that overlap and to the detector.

Clearly, alternatively, the field of view or cone may be adapted so asto not overlap at this position.

In one situation, the radiation blocking element engages the housing oris fixed to the housing (or forms part of the housing) and extends awayfrom the housing. Naturally, the radiation blocking element may formpart of any element of the assembly, such as a dome.

In one situation of the method:

-   -   one of the radiation detectors is positioned in the housing and        receives radiation within a field of view,    -   one of the radiation emitters is positioned in the housing and        emits radiation within an emission cone, the method further        comprising blocking radiation travelling in an overlap between        the field of view and the cone.

Then, the blocking step may comprise blocking the radiation with aradiation blocking element engages the housing or is fixed to thehousing (forms part of the housing) and extends away from the housing.

In one situation, the assembly further comprises a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   one of the one or more detectors and one or more emitters        comprises a sensor housing,    -   the receiver housing and the sensor housing overlap at least        partly when projected on to a first plane, and    -   the receiver housing and sensor housing overlap at least partly        when projected on to a second plane perpendicular to the first        plane.

In another situation, the assembly further comprises a receiver,wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   one of the one or more detectors and one or more emitters        comprises a sensor housing being at least partially inside the        second chamber, and    -   the sensor housing or its portion inside the second chamber,        having a volume not exceeding 20% of a volume of the second        chamber.

An aspect of the invention relates to an assembly comprising a receiverand a sensor, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   the sensor comprises a sensor housing being at least partially        inside the second chamber, and    -   the sensor housing or its portion inside the second chamber,        having a volume not exceeding 20% of a volume of the second        chamber.

An aspect of the invention relates to an assembly comprising a sensorand a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   the sensor comprises a sensor housing,    -   the receiver housing and sensor housing overlap at least partly        when projected on to a first plane, and    -   the receiver housing and sensor housing overlap at least partly        when projected on to a second plane perpendicular to the first        plane.

In this context, the first plane may be a plane defined by the receiverdiaphragm, but this is not required.

In this context, a housing will define an area or outer contour whenprojected on to a plane. An overlap thus is seen when the areas orcontours of the two housings overlap.

When the two housings overlap in the two projections, the overall extentof the assembly may be made smaller, which has advantages, such as if itis desired to position the assembly inside the ear canal of a person.

In a first preferred embodiment, the sensor housing is positioned atleast partly inside the receiver housing. Thus, the sensor housing mayhave an outer wall portion taking part in defining a chamber in thereceiver housing.

When the sensor is positioned inside the receiver housing, it willaffect the overall volume and thus the properties of the receiver. Thus,it may be desired that the sensor is rather small. In one embodiment, itis desired that the sensor housing has an outer volume not exceeding20%, such as not exceeding 10% or even not exceeding 5%, of an innervolume of the receiver housing. Usually, the receiver has a frontchamber, into which the sound outlet opens, and a second chamber on anopposite side of the diaphragm. In that situation, the sensor may beprovided in the second chamber and take up no more than 20%, such as nomore than 15%, such as no more than 10%, such as no more than 8% of avolume of the second chamber.

Naturally, the sensor housing may be positioned at least partly outsideof the receiver housing.

The sensor housing may be attached to the receiver housing.

In one embodiment, the receiver diaphragm and sensor housing overlap atleast partly when projected on to the first plane. In that situation,the receiver diaphragm need not be limited by the presence of the sensorwhich may extend in a chamber of the receiver, such as “under” thereceiver diaphragm. The size of the diaphragm is a factor in thedefinition of the maximum sound intensity which the receiver may output,and it is usually desired to provide as large a diaphragm as practicallypossible.

In one embodiment, the receiver housing and sensor housing, whenprojected on to the first plane, overlap an area of at least 10%, suchas at least 20%, such as at least 40%, such as at least 50%, such as atleast 75%, such as at least 90%, such as 100% of an area of the sensorhousing in the projection.

Alternatively or additionally, the receiver housing and sensor housing,when projected on to the plane perpendicular to the first plane, overlapan area of at least 10%, such as at least 20%, such as at least 40%,such as at least 50%, such as at least 75%, such as at least 90%, suchas 100% of an area of the sensor housing in the projection.

Alternatively or additionally, the receiver diaphragm and sensorhousing, when projected on to the first plane, overlap an area of atleast 10%, such as at least 20%, such as at least 40%, such as at least50%, such as at least 75%, such as at least 90%, of an area of thesensor housing

In one situation, the sensor housing is box-shaped and has 6 outer wallportions, which are pair-wise parallel. Often, the sensor has roundedcorners and edges. In this situation, the sensor housing may be selectedso that a wall portion with a largest surface area has a surface areanot exceeding two, such as not exceeding 1.8, such as not exceeding 1.5,such as not exceeding 1.3, times a surface area of a wall portion havingthe smallest surface area. In the situation where all wall portions havethe same size would be the shape of a cube. In this context, the area ofa wall portion may be that defined by the wall portion when projected onto a plane perpendicular to the wall portion or a portion of the wallportion.

In this situation, it is not desired to have e.g. a long and flat sensorhousing, as the sensor housing, positioned in the receiver housing, maybe exposed to very high sound pressures which may deform or vibrate toolarge wall parts of the sensor.

On the other hand, a certain inner volume is desired of the sensorhousing, and thus, this more cube shaped shape is preferred as it allowsthe desired inner volume while keeping the wall parts relatively small.

In addition or alternatively, vibration of the sensor housing wall partsmay be prevented by providing relatively stiff or thick walls of thesensor housing such as walls with a thickness of at least 0.5 mm, suchas at least 0.75 mm, such as at least 1.0 mm, such as at least 1.5 mm,such as at least 2 mm, such as at least 2.5 mm, such as at least 3 mm.

The other of the emitter and the detector may be positioned outside ofthe receiver housing or, for example, at least partly in the firstchamber of the receiver. Then, the portion of the emitter/detectorinside the first chamber may have a volume not exceeding 20% of a volumeof the first chamber.

Naturally, it may be desired to allow radiation to travel between theinner volume of the second chamber, such as if the emitter is providedfully within the second chamber, and the outside of the receiver housingto the tissue. In that situation, it is not desired to have soundpassage along the same route, so a window, lens or the like may beprovided in the receiver housing wall so as to allow radiation to passbut prevent sound from passing.

Actually, another interesting aspect is as that above where at least aportion of the emitter and/or the detector is positioned in the firstchamber. Usually, the first chamber is more volume critical, but asemitters and detectors may be made extremely small, their presence inthe first chamber would not be detrimental.

An aspect of the invention relates to an assembly comprising a receiverand a sensor, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   the sensor comprises a radiation emitter and a radiation        detector, one of the radiation emitter and the radiation        detector being at least partially inside the second chamber.

Then, the portion of the one of the emitter and the detector inside thesecond chamber may have a volume not exceeding 20% of a volume of thesecond chamber.

In one situation, the method further comprises operating a receiver,comprising:

-   -   a receiver housing with a receiver housing wall part comprising        a sound output,    -   a receiver diaphragm defining, with an inner surface of the        receiver housing, a first chamber in the receiver housing,

the method comprising providing the housing, a sensor with a sensorhousing and the receiver so that:

-   -   the receiver housing and a sensor housing overlap at least        partly when projected on to a first plane, and    -   the receiver housing and sensor housing overlap at least partly        when projected on to a second plane perpendicular to the first        plane.

In another embodiment, the method further comprises operating a receivercomprising:

-   -   a receiver housing,    -   a receiver diaphragm defining, with an inner surface of the        receiver housing, a first chamber in the receiver housing having        a sound output, and a second chamber in the receiver housing,

the method comprising providing the housing, a sensor with a sensorhousing and the receiver so that:

-   -   one of the one or more detectors and one or more emitters        comprises a sensor housing being at least partially inside the        second chamber, and    -   the sensor housing or its portion inside the second chamber,        having a volume not exceeding 20% of a volume of the second        chamber.

An aspect of the invention relates to a method of providing an assemblyof a receiver and a sensor, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing, and    -   the sensor comprises a sensor housing being at least partially        inside the second chamber,

the method comprising providing the sensor housing or its portion insidethe second chamber, having a volume not exceeding 20% of a volume of thesecond chamber.

An aspect of the invention relates to a method of providing an assemblycomprising a sensor and a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   the sensor comprises a sensor housing,    -   the method comprising providing the receiver and sensor so that:        -   the receiver housing and sensor housing overlap at least            partly when projected on to a first plane, and        -   the receiver housing and sensor housing overlap at least            partly when projected on to a second plane perpendicular to            the first plane.

Then, the sensor housing may be positioned at least partly inside thereceiver housing.

The sensor housing may have an outer volume not exceeding 20% of aninner volume of the receiver housing.

The sensor housing may be box-shaped and have 6 outer wall portions,where a wall portion with a largest surface area has a surface area notexceeding twice a surface area of a wall portion having the smallestsurface area.

The sensor housing may be positioned at least partly outside of thereceiver housing.

The sensor housing may be attached to the receiver housing.

The method may further comprise one or more conductors connected to thesensor housing and extending outside of the sensor housing, at least apart of the conductor(s) extending inside the receiver housing.

The receiver diaphragm and sensor housing may overlap at least partlywhen projected on to a first plane.

The receiver housing and sensor housing, when projected on to a firstplane, may overlap an area of at least 10% of an area of the sensorhousing in the projection.

An aspect of the invention relates to a method comprising providing anassembly of a receiver and a sensor, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   the sensor comprises a radiation emitter and a radiation        detector, one of the radiation emitter and the radiation        detector being at least partially inside the second chamber.

Then, the portion of the one of the emitter and the detector inside thesecond chamber may have a volume not exceeding 20% of a volume of thesecond chamber.

It may be desired to provide a symmetrical design so that the sameassembly may be used in both the left and the right ear canal of aperson. In this case, it may be desired to have one lay-out of thedetectors/emitters in one ear canal and a mirrored set-up in the othercanal. Providing both set-ups in an assembly arrives at a symmetricdesign.

Preferably the mirroring is performed via a vertical plane.

In one situation:

-   -   the radiation detector(s) are positioned in or symmetrically on        either side of a plane extending through the housing and/or    -   the radiation emitter(s) is/are positioned in or symmetrically        on either side of the plane.

In this context, symmetrical on either side means that oneemitter/detector is mirrored into another one via the plane. In thiscontext, mirroring means representing the element on the opposite of theplane perpendicularly on the plane and in the same distance from theplane.

In one situation, the housing is configured to be positioned so that theplane is at least substantially vertical such as when the housing ispositioned in the ear canal of a person standing up and looking straightahead.

Symmetry may be obtained in two manners: providing two elements, one oneither side, or providing one element positioned in the plane orextending equally on either side of the plane.

In one situation, at least one detector is positioned to receiveradiation travelling in the plane.

It may be desired to provide detector(s) only in the plane and emitterson either side of the plane.

In one situation, the method comprises:

-   -   positioning the radiation detector(s) in or symmetrically on        either side of a plane extending through the housing and/or    -   positioning the radiation emitter(s) in or symmetrically on        either side of the plane.

The housing may be positioned in an ear canal so that the plane is atleast substantially vertical.

At least one detector may be positioned to receive radiation travellingin the plane.

The method may comprise providing two of the assemblies and providingone in a left ear canal of a person and the other in the right ear canalof the person.

Clearly, the operation of the sensors of one assembly may be adaptedaccording to which ear canal it is provided in. Thus, the operation ofthe assemblies may differ from left to right side. Usually, thisdifference will relate to mirrored operation, so that, for example, ifthe right side emitter(s) are operated in the left ear canal, the leftside emitter(s) may be operated in the right ear canal.

Thus, the assemblies may be programmed according to which side they areprovided in.

Also, if sensors are provided in both assemblies, the sensor in only oneassembly need be operated at the time, such as to save energy. Thesensor of the other assembly may occasionally or periodically make ameasurement to compare the quality to the operating sensor of the otherassembly. If that measurement quality is better, the operation may shiftto the other assembly. Operation may also shift if the operatingassembly is low on power.

Thus, the method may comprise feeding information e.g. from a processorin a BTE or from a processor in an earphone or a mobile telephone to anassembly as to whether the assembly is (to be) used in a right ear of aleft ear. Then, the sensor of the assembly may, based on thatinformation, operate some emitters/detectors and not others. Clearly, ifthe assembly was informed that it was to be used in the other ear, itmay operate other emitters/detectors. In the above situation where theassemblies have mirrored detectors/emitters, one of a mirrored pair maybe operated in the left ear and the other of the pair in the right ear.

The method further may comprise evaluating, between two assemblies, suchas when used in the ear canals of a person, which assembly has the bestsignal quality from the optical sensor(s) and the rendering of theoptical sensor of the other assembly inactive. Clearly, the inactivesensor may still perform some sensing in order for its signal quality tobe known so that it may be rendered active (and the presently activesensor may then be rendered inactive), if its signal quality increasesor surpasses that of the presently active sensor (in the other ear).

In another embodiment, both assemblies in both earcanals may beintentionally activated, for example, if certain redundancy is requiredin the sensing, or for example, if sensing from both ear canals willimprove the quality of the processing by a processor. It has been foundpreferable to provide at least most of the detectors and/or emittersrather close to the portion of the housing which is the farthest intothe ear canal or closest to the ear drum.

Usually, the housing is configured to also output sound toward the innerear. Thus, the housing has a sound output. Clearly, the housing may thencomprise a receiver or may have an input for receiving sound from asound generator not provided in the housing, such as provided in a BTEportion connected to the housing.

In one situation, the housing is oblong with a first end portion and asecond, opposite end portion, the housing comprising a sound outlet inor at the first end portion, where a majority of the radiationemitter(s) and a majority of the radiation detector(s) is/are positionedcloser to the first end portion than the second end portion.

The position of an emitter may be that of a centre of the emittingportion of the emitter.

The position of a detector may be a centre of a sensitive portionthereof.

The positions may be determined in a projection of the emitters anddetectors on a longitudinal axis, such as a symmetry axis, of thehousing.

The housing may comprise a spout through which sound is output. Thisspout may not be seen as a part of the housing.

The housing may have a symmetrical shape with the first and second endportions being mirrored in a plane perpendicular to the longitudinalaxis.

In one situation, the assembly further comprises a receiver positionedin the housing, where a majority of the radiation emitters and theradiation detectors are positioned, in a projection on to a longitudinalaxis of the housing, closer to the first end portion than a centre ofthe receiver.

The majority may be 50% or more, such as 60% or more, such as 75% ormore.

A dome may be provided for attaching the housing in and ear canal.Often, the dome is attached in the front or inner portions of thehousing and thus where the emitter(s) and detector(s) are desired. Then,the dome or portions thereof may be transparent or translucent to theradiation, or be made such that they guide the radiation to wantedpositions, or block them from reaching unwanted positions.

In one embodiment of the method, the housing is oblong with a first endportion and a second, opposite end portion, the housing comprising asound outlet in or at the first end portion, the method comprisingpositioning a majority of the radiation emitter(s) and a majority of theradiation detector(s) closer to the first end portion than the secondend portion.

In another embodiment, the method comprises a step of positioning areceiver in the housing, where the step of positioning the majority ofthe radiation detector(s) and the majority of the radiation emitter(s)comprises positioning a majority of the radiation emitters and theradiation detectors are positioned, in a projection on to a longitudinalaxis of the housing, closer to the first end portion than a centre ofthe receiver.

Another aspect of the invention relates to an assembly of a receiver, aradiation emitter, a radiation detector and an assembly housing,wherein:

-   -   the receiver has a receiver housing and is positioned inside the        assembly housing,    -   the radiation detector is positioned in the assembly housing and        has a reception direction along a first direction,    -   the radiation emitter is positioned in the assembly housing and        has an emission direction along a second direction, an angle        existing between the first and second directions,    -   one or more windows transparent to the radiation are provided in        the assembly housing for allowing radiation from the emitter to        exit the assembly housing and radiation from outside of the        assembly housing to reach the detector.

In this context, a radiation emitter and a radiation detector may be asdescribed above. As mentioned, the radiation wavelength may be selecteddepending on the parameter sought detected. Wavelength selection may bemade by selecting the emitter and/or by employing filters.

A radiation emitter will emit radiation in a cone, as described above,inside which an emission direction may be defined, usually in thedirection receiving the highest intensity of radiation and/or a symmetryaxis of the emitter.

Also, the detector will have a reception characteristic defining a maindirection, such as a symmetry axis of the reception pattern

A window is transparent to the wavelength in question, if it absorbs,reflects or scatters no more than 50% of the radiation at thatwavelength when launched perpendicularly through the window. Usually, amuch lower absorption/scattering/reflection, such as no more than 30%,20%, 10%, 5% or less is desired.

The assembly housing may be configured to be positioned within an ear orear canal of a person. The assembly may be a hearing aid or a hearable,or a part thereof. The assembly may comprise also other elements, suchas batteries, microphones, processors or the like. Alternatively, suchcomponents may be provided in other elements connected to the presentassembly, as in the situation where hearing aid has an In The Ear (ITE)portion forming the assembly and a Behind The Ear (BTE) portionconnected to the ITE and having for example the battery.

The emitter or detector may be provided in the receiver housing or in acut-away thereof as described above in relation to the overlappingfashion. Alternatively, both the emitter and the detector may bepositioned outside of the receiver housing. The emitter/detector may beattached to the outer side of the receiver housing and/or to e.g. aninner surface of the assembly housing.

The directions have an angle to each other. When the directions aredirectly opposite to each other, the angle is 180 degrees.

If the angle is zero (the directions are parallel), a predefined minimumdistance may be desired between the two directions in order to ensurethat radiation passes from the emitter to the detector, via thesurroundings of the assembly housing, via a route of at least anotherminimum distance.

When the angle is non-zero, the directions may be pointed toward eachother to form an overlap, if desired, between the cone and the field ofview. Alternatively, the directions may be selected so that no overlapis seen.

In some situations, it may be desired to have the directionsperpendicular to each other, such as between 20 and 50 degrees orbetween 45 and 135 degrees, such as between 60 and 120 degrees. It mayalternatively be desired to have the directions opposite to each other,so that the angle is around 180 degrees, such as between 150 and 210degrees.

If the assembly housing has 6 rather straight sides (may have roundedcorners/edges) perpendicular to each other, it may be desired that thedirections each are at least substantially perpendicular to a side. Inthis manner, the emitter/detector may be attached to a side or inrelation thereto.

In one situation, a number of radiation emitters are provided. These maybe positioned in a variety of manners, such as with different emissiondirections. It may be desired that the emitters emit radiation indifferent directions so as to emit radiation into as large a portion ofthe surroundings, such as an ear canal, as possible. In one situation,the emitters are positioned in a single plane and with differentdirections within that plane. In other situations, one emitter may havea direction perpendicular to that of another emitter.

In addition or alternatively, multiple detectors may be provided so asto e.g. be able to collect radiation from as large a portion of thesurroundings as possible. In one situation, the detectors are positionedin a single plane and with directions within that plane. In othersituations, one detector may have a direction perpendicular to that ofanother detector.

In one situation, the receiver has therein a membrane provided in amembrane plane. In this situation, it may be desired that a direction ofan emitter and/or a detector is provided at least substantially in themembrane plane, perpendicular or parallel thereto. Alternatively, theangle between the emitter and/or detector direction and the plane may be5-85 degrees, such as 10-30 degrees, 20-40 degrees, 30-50 degrees, 40-60degrees, 50-70 degrees, or 60-80 degrees. Clearly, an emitter may haveone angle to the plane and a detector another angle. Also, the emitterdirection and detector direction may, when projected on to the plane,have different angles between them.

In one situation, it is desired to have the radiation interact with thetissue positioned vertically and below the assembly housing. Thus, itmay be desired that an emitter and/or a detector has its direction atleast substantially vertical, when positioned in the ear canal of aperson standing up. For example, this direction may be no more than 40degrees, such as no more than 30 degrees, such as no more than 20degrees, such as no more than 10 degrees from vertical.

Certain portions of ear canal may be more favourable to measure thephysiological signals than other areas. For example, areas closer toeardrum may be preferred, or bottom area. In one embodiment, it isdesired to avoid certain areas of ear canal, for example, areas of earcanal where there is a lot of motion due to physical activities of aperson which cause body volumes close to certain parts of ear canal tomove and hence create distortions that result in inferior measurementsof physiological signals. The emitter or detector may be positioned inthe hearing device such as to avoid such undesirable areas.Alternatively, the whole hearing device may be moved, e.g. shiftedlongitudinally or rotated in ear canal, to change the area ofinteraction of detector or emitter with ear canal.

Thus, the method may comprise the step of determining relative movementbetween an ear canal and the assembly housing and operating inaccordance with the relative movement determined.

Relative movement may be determined using an accelerometer. This type ofsensor will describe e.g. that the person is moving, such as running.This may displace the housing in the ear canal and may affect theoptical measurement.

Another cause for relative movement is when the person speaks. In thissituation, portions of the ear canal may deform causing relativemovement of the portions with respect to the assembly housing, eventhough the housing may itself be more or less stationary with respect tothe person's body. Thus, the determining step may comprise determiningspeech. A voice pickup sensor may be used for determining speech. Avoice pickup may determine speech from sound or vibrations transportedin the head of the person. When the speech, for example, exceeds athreshold limit, relative movement may be assumed or determined.

Yet another manner of determining relative movement is from the outputof the optical sensor itself. E.g. a PPG signal will vary when relativemovement takes place, so the movement may be determined from the PPGsignal.

The action taken when relative movement is determined may be to controlthe hearing device to prompt a user or operator to alter the position orrotation of the housing in the ear canal. Thus, the reaction to therelative movement may be a displacement of the housing along thelongitudinal direction of the ear canal. Alternatively or additionally,the reaction may be a rotation of the housing in the ear canal.

This prompting may be provided to the user via a receiver, if present,provided in the assembly housing. The assembly may be configured tooutput such a prompt when the movement is determined.

Other reactions could be to select particular emitter(s) or detector(s)when relative movement is seen. In one embodiment, a downwardly(vertical) detector may be selected.

Yet another reaction could be to search for useful sets of one or moreemitter and one or more detector by simply activating different suchsets of emitter(s) and detector(s) and determining a set with asufficient signal quality.

Numerous manners exist of ascertaining that the assembly is positionedcorrectly in the ear canal of a person. In one situation, the assemblymay have an indication enabling an operator to orient the assemblycorrectly during insertion. In another situation, the assembly may havemultiple emitters and/or detectors with different directions, so thatthe emitter and/or detector with the lowest angle to vertical anddownward may be selected or operated.

In the first situation, the window(s) of the assembly housing may assistthe operator in determining how to orient the assembly during insertion.In other examples, the assembly housing may be fitted to the ear canalso that the orientation is defined by the shape. Otherwise, the housingmay have a visible indication, such as an arrow. Alternatively, a cableattached to the assembly housing may have an indication or be fastenedin a particular manner to the housing indicating to the operator how toorient the assembly housing. Actually, the cable may be used forrotating the assembly while positioned within the ear canal.

As to the second situation, this may employ a sensor, such as anaccelerometer, to this effect. In one situation, multiple emittersand/or detectors may be positioned with different angles to a horizontalplane. These may be positioned in a plane perpendicular to a horizontaldirection, such as around a longitudinal direction or axis of thehousing. Preferably, the axes are distributed in relation to thehorizontal plane, such as at a more or less defined angular spacing, sothat one will have a lower angle to vertical than others. Often, theassembly housing has a sound output for receiving sound from thereceiver and for outputting this sound to the surroundings. Asmentioned, the assembly housing may be shaped to or configured to bepositioned in the ear canal of a person. In that situation, the soundoutput would be directed toward the inner ear and the ear drum. Theassembly housing may comprise a spout or the like defining the soundoutput.

In such situations, it is preferred that the radiation interferes withthe tissue close to the sound output or even closer to the ear drum.

Thus, in some embodiments, the radiation emitter and/or the detector isdirected at an angle below 90 degrees to a direction of the soundoutlet, such as the direction of sound emitted from the sound outlet. Ifthe sound outlet is in the shape of a spout, this will normally be asymmetric element, where the symmetry axis may be the direction of thesound outlet.

The sound outlet may also have the shape of an opening in a planesurface. In that situation, the direction of the sound outlet may be asymmetry axis of the opening, such as if drilled or punched-out.Alternatively, the direction may be perpendicular to the surface havingthe sound outlet.

When the angle is below 90 degrees, radiation is launched more in thedirection of the sound outlet than in the opposite direction and/orradiation is detected from that direction.

Naturally, the angle may be as low as possible, such as below 80degrees, below 70 degrees, below 60 degrees, such as below 50 degrees or45 degrees or even 30 or 20 degrees. The angle may be 10-80 degrees,such as 11-70 degrees, such as 12-60 degrees, such as 15-50 degrees.

In that or another situation, the windows in the assembly housing fortransmitting the radiation may also be positioned close to the soundoutput. The windows preferably are positioned closer to the sound outputthan to an opposite end of the assembly housing. If the sound outlet isin the form of a spout, it may be desired to provide the windows in thespout. Alternatively, as the spout may be used for attaching the housingto e.g. a dome, it may be desired that the windows are not in the spoutbut close to the spout, such as closer to the spout than to an oppositeend of the assembly housing.

The assembly housing may have a generally longer dimension, which may bethe longest Euclidian distance between any portions of the assemblyhousing. Then, at least one of the windows may be positioned no morethan 40%, such as no more than 30%, such as no more than 20% of thelongest dimension from the sound outlet or the base of the spout ifpresent.

In general, multiple detectors or multiple emitters may be used. Often,multiple detectors would be positioned at different positions around thereceiver housing so as to receive radiation from different directions.It may be desired that the detectors do not have overlapping fields ofview so as to increase the tissue volume from which radiation may bereceived.

In one embodiment, a controller is provided for receiving the output ofthe detector(s) and for feeding the emitter(s). Naturally, multiplecontrollers may be used. A controller may be any type of processor, DSP,ASIC, monolithic or formed by a number of such elements.

In one situation, the controller is positioned in the receiver housing.Then, if the emitter(s) and/or detector(s) is/are not provided in thereceiver housing, the controller may be connected to theemitter(s)/detector(s) via electrically conducting vias in the receiverhousing. Such vias or connections may also be used for outputting asignal from the controller to e.g. an external unit receiving thissignal. The controller may determine e.g. the pulse or the like from theoutputs of the detectors and thus output information indicating thispulse or the like, or the controller may output information derived fromthe signals from the detectors, so that the final analysis may be madeby an element, such as another controller, receiving the output of thiscontroller.

Thus, a controller may be provided in the receiver housing andelectrical connections be provided from the controller through thereceiver housing to the emitter(s) and/or the detector(s). Also,electrical connections may be provided through the receiver housing wallfor powering the controller and/or for transferring instructions or datato or from the controller.

The controller can be provided in the RIC housing for example, on thesame PCB as the PPG components.

The controller can be positioned also in a connector attached to RIC,such as described in for example EP3343952 or EP3116240.

In yet another embodiment, the controller may be attached to a detectoror emitter.

The assembly may further comprise one or more conductors connected tothe sensor housing, such as the above electrically conducting elements,in order to e.g. receive a signal. Such conductors will then extendoutside of the sensor housing but will preferably extend, at least for aportion of a length thereof, inside the receiver housing, such as toelectrically conducting elements on or at an outer surface of thereceiver housing so that the signal from the sensor may be delivered tosuch conducting elements, via the conductors. Then, the conductors maybe at least partly protected by extending inside the receiver housing.In one situation, the electrically conducing elements of the sensor maybe provided in a wall portion of the sensor housing facing a wallportion of the receiver housing. This portion of the receiver housingmay comprise, as a portion of the conductors, electrically conductingelements to which the conducting elements of the sensor housing areconnected.

In this context, the conductors may extend within the inner volume ofthe housing or e.g. within the housing walls thereof.

In that situation, the connections for both the receiver and the sensormay be made to the receiver housing. The electrically conductingelements for these connections may be provided in the same wall portionof the receiver housing, such as a wall portion opposite to a wallportion in which the sound output is provided.

Naturally, alternatively, the conductors for the sensor may simplyextend around the receiver housing and away therefrom.

All (or part of) components can be mounted in (flex)PCB and thenselectively attached to outer housing.

In general, when multiple detectors are provided, it is possible tomonitor the output of the detectors and/or combine the output thereof.For example, if the ear canal changes shape or the housing changesposition in the ear canal, one detector may receive an increased signaland another detector may receive a reduced signal. This may be thesituation if the detectors are positioned so that one moves closer tothe tissue by the movement and the other moves farther away from thetissue by the movement (if the two detectors are positioned oppositelyon the housing). Thus, adding the two signals may arrive at a combinedsignal which is more independent of this movement. of course signalsfrom any multiple of detectors/emitters can be combined (with anymathematical operation) to improve the PPG signal and to reduce and(movement induced) noise e.g. by compensation.

In the following, preferred embodiments of the invention will bedescribed with reference to the drawings:

FIG. 1 illustrates an embodiment of an assembly with an optical sensor,

FIG. 2 illustrates a receiver connected to a dome and having an opticalsensor,

FIG. 3 illustrates a receiver with multiple detectors,

FIG. 4 illustrates how to launch radiation through the receiver wall,

FIG. 5 illustrates a receiver with a large emitter/detector at the farend,

FIG. 6 illustrates the many possibilities of directions of the emitterand detector,

FIG. 7 illustrates an assembly housing having windows for radiation topass and

FIG. 8 illustrates a receiver with a controller.

FIGS. 9-12 illustrate a symmetrical set-up with emission cones and fieldof view,

FIG. 13 illustrates emitters or detectors also at corners of a housing,

FIG. 14 illustrates a housing in an ear canal, and

FIGS. 15 and 16 illustrate embodiments with no overlap between thefields of view and the cones.

In FIG. 1, an assembly of a receiver with a receiver housing 20, anouter housing 41 attaching the receiver housing 20 to a spout 46 and aradiation emitter 44. In a recess of the receiver housing, a lightreceiver or detector 42 is provided.

The receiver housing 20 has a lower indentation or cavity 28 in whichthe detector 42 is positioned.

Numerous alternatives exist. The cut-out in the receiver housing 20 maybe made large enough to accommodate both the emitter and the detector.Also, the emitter/receiver received in the recess may instead beprovided fully within the receiver housing 20 or partly therein so as toe.g. protrude from the receiver housing.

A flexible PCB 421 is illustrated extending from the right end of thereceiver housing 20, below the receiver housing and between the receiverhousing and the detector and the emitter, respectively. This PCBprovides the electrical contacting to the receiver and detector.Contacting to the receiver housing could take place at the right sidethereof, so that all elements may be contacted at the same side of thereceiver.

It is noted that the flexible PCB 421 of FIG. 1 may be useful also in amore general setting, as it may also be suitable for use in the receiverhousing, when the detector/emitter is fully or partly provided therein.The motor could also be connected to this flexible PCB.

This embodiment may be rather simply assembled, as the emitter anddetector may be attached to the flexible PCB and may then be forced intothe desired position by the outer housing 41.

The portion 411 of the housing 411 is made transparent to the radiationoutput by the radiation emitter 44.

It is seen that an angle, a, is provided between the symmetry axis(arrows) or centre of the line or cone of sight of the detector andemitter. Thus, radiation has to pass a distance from the emitter beforereaching tissue from which it may be reflected to the detector.

Also, the direction of the spout 46 is indicated as well as an angle, β,between the axis of the emitter 44 and the direction of the spout. Itmay be desired at β is less than 90 degrees for the detector and/or theemitter.

As mentioned above, the light preferably travels at least a minimumdistance in the tissue from the emitter to the detector. The light orradiation may thus be reflected/scattered more than once and maytherefore travel around corners. Therefore, the emitter and detectorneed not be positioned on or at the same side (as illustrated in FIG. 1)of the receiver housing 20. In fact, the emitter and receiver may bedesired positioned on different sides, such as one at the top and one onthe left, right, back, front or the lower side of the receiver housing20.

In FIG. 2, a receiver 20 is placed in a receiver assembly housing 41which is, in turn, also accommodating a spout (nozzle) 46 connected to adome 49. The receiver may, naturally, be connected to a number of otherelements or within other housings.

In this figure, four exemplary positions, A, B, C, D and E areillustrated. One or more of these may be used for the emitter and one ormore of the remaining ones may be used for the detector.

In FIGS. 9-12, a receiver housing or outer housing is illustrated havingemitters 44 positioned along the sides thereof as well as on the top (inthe direction illustrated in FIG. 9) as well as a detector 42 in thebottom. In FIGS. 10 and 11 the emission cones and field of view areillustrated, where the emission cones and field of view may be definedas FWHM angles, for example.

In FIG. 13, alternative positions are indicated, which may be not onlyon or at the plane sides but also at corners or edges.

Preferably, the emitters 44 are positioned symmetrically around or in avertical symmetry plane of the housing. In that situation, the samehousing may e.g. be used in any ear canal of a person. Preferably, atleast one emitter or detector is directed directly downwardly orupwardly, as signals to/from a vertical direction are interesting.

Naturally, if the detector(s) and/or emitter(s) is/are positioned in thereceiver housing, the receiver may be directed, vis-à-vis the outerhousing so that they have the desired directions relative to verticalwhen the outer housing is inserted in an ear canal. Ear canals may beoval and so may the outer housing. However, as the oval shape is notnecessarily directed, vis-à-vis vertical, identically in all persons,the outer housing may be rotated differently vis-à-vis vertical. Thisrotation may be counter-acted by rotating the receiver housing insidethe outer housing.

Clearly, in this situation, sufficiently large windows/lenses may beprovided in the outer housing in order to allow for such rotationwithout unnecessary blocking of the radiation.

In FIG. 14, the outer housing with the dome is illustrated inside an earcanal with an ear canal top 50, an ear canal bottom 52 where a dome 49is provided proximate the ear drum 54.

Clearly, an emitter or detector may be provided inside the receiverhousing and/or outside of the receiver housing but still in the assemblyhousing 41.

As embodiments exist in which no receiver is present at all, thepositions in/on the receiver are not essential. Clearly, the presentinvention is targeting an in-the-ear-canal position of opticalmeasurement. Very often, it is desired to provide sound also in the earcanal, a receiver is an obvious choice. However, a receiver may also bepositioned in other positions and a sound guide be provided to andusually through the housing 41 to an output thereof—such as the spout46.

In FIG. 3, a receiver is illustrated having an upwardly directed emitter44 provided in the first chamber and two detectors 42 positioned in thesecond chamber. This merely illustrates that multiple emitters and/ordetectors may be used, and that these may be positioned in differentpositions completely within, partly within or outside of the receiverhousing.

When multiple detectors are used, it is preferred that they havenon-overlapping fields of view, such as when directed in differentdirections. In FIG. 3, the two detectors look in different directions(one is directed downwardly and one to the side) and do not overlap

Providing multiple detectors increases the volume of the tissue fromwhich radiation can be received.

In the same manner, multiple emitters may be used in order to provideradiation to a larger tissue volume. Again, this may increase theoverall volume from which radiation may be received. In FIG. 3, anadditional emitter 44 pointing downwardly is illustrated.

As mentioned above, it may be desired to ensure that the radiationtravels at least a predetermined distance in the tissue before reachingthe detector. This may be ensured by tailoring the fields of view of theemitter (could also be called emission cone) and detector so thatradiation has to move from one emission cone to the other and then tothe detector. Alternatively, a blocking element, as that illustrated at43, may be provided which blocks a portion of a field of view of one ofthe detector and emitter—or both—so as to again force the radiation totravel further before reaching the detector. In FIG. 3, a narrowemission cone is illustrated in unbroken lines and a wider, partlyblocked, emission cone is illustrated in dashed lines.

In FIG. 4, different embodiments are seen when the detector 42 or theemitter 44 is provided in the receiver housing 20. In this situation, awindow 50 may be provided for allowing radiation to pass from inside tooutside of the housing wall (or vice versa). Also, a mirror 45, or otheroptics, or an optical fibre 47 may be provided for guiding the radiationto/from the emitter/detector from/to the window 50. The window 50 mayhave a particular shape and/or be replaced by a lens or the like inorder to adapt the field of view if desired.

In FIG. 5, an embodiment of a receiver 20 is seen comprising a diaphragm24 and a motor 27. Also provided in the receiver housing 20 is aradiation emitter 42 or a detector 44 which in this example extends frombelow to above the plane of the diaphragm which therefore in that ismade smaller. The advantage of providing the emitter/detector in the farend of the housing 20, compared to the sound output 23, has theadvantage that the diaphragm is usually driven by the motor at aposition rather close to the output—compared to the situation where theoutput was provided at the end of the emitter/detector. The point ofdriving the diaphragm usually has the largest deflection of thediaphragm, and the closer this position is to the output, the largersound intensity can be output.

FIG. 6 illustrates the receiver housing 20 or the assembly housing 41and a number of the directions which could be used for emitters and/ordetectors. No boundaries really exist as to which directions to use.

In FIG. 7, a receiver housing 20 or an assembly housing 41 isillustrated having two windows directed at 90 degrees to each other.

When the windows are also visible in the assembly housing, theorientation of the assembly housing may be ascertained or corrected.This may be the situation where a particular direction is desired of theradiation emitted or received and/or where it is desired that theradiation has interacted with tissue with a particular positionvis-à-vis the assembly or within the ear canal. In particular, asdescribed above, it may be desired that the tissue is that directlybelow, vertically, the assembly, especially when the person is standingup. Then, the positions of the windows may be used by the operator wheninserting the assembly so that the window is pointed downwardly, so thatthe radiation emitted through the window or received through the windowis to or from that direction.

Actually, the ear canal of a normal person has an oval cross section.Thus, when the housing 41 has a corresponding oval shape, the directionof the radiation output and of the field of view of the detector(s) maybe rather simply controlled by controlling the direction of the opticalelements in relation to the housing 41. Often, however, the outerhousing has a shape corresponding to that of the receiver, i.e. slightlyoblong with a quadratic cross section perpendicular to the longitudinalaxis and with rounded corners.

In the situation where the emitter(s) and detector(s) are attached to orin the receiver housing, this may simply be obtained by orienting thereceiver housing within the outer housing. Receivers often are at leastslightly oblong with a quadratic cross section perpendicular to theirlongitudinal axis (see FIG. 7), where the cross section is oblong andnot squared (and has rounded corners). This oblong cross section thusfacilitates orienting the receiver housing correctly in the outerhousing.

A slightly complicating factor is that the ear canal shape is not thesame from person to person so that the longest dimension in the ovalcross section will not necessarily have the same angle to vertical forall persons. Thus, the orientation vis-à-vis vertical of an outerhousing with an oval cross section may differ from person to person.Then, so may the orientation of the receiver housing within such outerhousings and/or the emitter(s) and detector(s) if not attached to thereceiver housing.

In case the oval cross section of an ear canal is too rotated, thedesired directions of the radiation may be obtained by attaching thedetector(s)/emitter(s) at an angle to the receiver housing, such as incorners/edges thereof.

Naturally, the shape of the outer housing need not correspond entirelyto that of the ear canal. The outer housing may be made smaller and beattached in the ear canal using e.g. a dome.

Often, however, an outer housing may be designed which may be used inboth ear canals of a person. Then, manufacture will be easier, as twohearing aids for that person may be made from a single process or asingle mold.

In one embodiment, however, the outer housing is made especially to theparticular ear canal, so that the definition and manufacture of thehousing may include the positioning and building-in or including of anywindows or the like.

It may also or alternatively be desired to provide the emitters anddetectors or at least a majority thereof close to the ear drum, such asin the portion of the receiver and/or outer housing which is the closestto the ear drum.

As indicated in FIGS. 9-12, most of the emitters and detector(s) arepositioned in that half of the housing which is closest to the spout 46.Usually, the spout or sound output is directed toward the inner ear.

FIGS. 15 and 16 illustrate different embodiments where there is nooverlap between the fields of view and cones. It is seen that thepositions of the detectors and emitters may be selected for a number ofpurposes, one being no overlap and others being the desired direction(s)to output radiation to or receive radiation from.

These assemblies may be used in different situations, such as dependingon the angle between vertical and the longest dimension of the ovalityof the ear canal. If this longest dimension is rotated sufficiently far,it may be desired to provide the emitters/detectors in the edges/corners(FIG. 16) in order to have the emission and detection from the desireddirections (often downwardly). An alternative would be to rotate thereceiver housing in the ITE housing, but this is often not possible, asthe receiver housing exterior shape and the ITE housing interior shapedo not often allow a sufficiently large rotation of the receiver housingwhen provided in the ITE housing. Then, a solution would be so use areceiver housing with the alternative positions of thedetectors/emitters.

Normally, the cable connecting the ITE and the BTE parts of the hearinginstrument keeps the device in the optimal orientation/position.

The housing may be fastened in the ear canal using a dome, double dome,custom dome, custom mould, sportslock or the like.

FIG. 8 illustrates an embodiment where the receiver 20 is provided inthe assembly housing 41 but neither of the emitter or detector isprovided in or at the receiver. The receiver however, comprises acontroller 201 configured to receive the output of the detector and/orto feed the emitter. This may be performed via electrical connections202 through the receiver housing wall. Naturally, electrical conductorsto/from the emitter/detector/controller are also desired. In thismanner, the controller is protected in the receiver and may be connectedto the emitter/detector later. Clearly, the emitter/detector mayalternatively be provided in the receiver housing if desired.

The connections 202 may also be used for receiving information or powerto the controller 201 from an external source, such as a battery oranother controller. Also, the connections may be used for outputting asignal from the controller 201. The controller 201 may analyse theinformation output of the detector(s) and then output a result of thisanalysis, such as a pulse of the person. Alternatively, the controller201 may output the data received from the detector(s) or a result of ananalysis thereof, which result requires further analysis of the externalcontroller.

If further detectors or sensors are provided, these may also be providedin the receiver housing or outside thereof and connected to thecontroller in the same manner. Such sensors may be used for e.g.determining an orientation of the person or assembly.

Also, the receiver(s) may be controlled so as to only be operated atparticular points in time, such as according to a schedule. If multiplereceivers are provided, one or more may be operated and others not. Thecontroller may facilitate this control.

Also, the controller may perform noise cancelling or reduction of thesignals from the detectors if desired.

Thus, the present assembly may be used, as described, in a hearing aidor hearable. Naturally, such hearing aid or hearable may comprise otherelements, such as a battery, antenna or coil, processor, amplifier,other circuits, or the like.

EMBODIMENTS

1. An assembly of at least one radiation detector, at least oneradiation emitter and a housing configured to be positioned inside theear canal of a person or animal, the detector(s) and emitter(s) beingprovided in or on the housing, the emitter(s) being configured to emitradiation away from the housing and the detector(s) being configured toreceive radiation directed toward the housing.

2. A method of providing an assembly according to embodiment 1, themethod comprising connecting the emitter(s) and detector(s) to thehousing.

3. The assembly according to embodiment 1, wherein one or more of thedetector(s) and/or one or more of the emitter(s) is/are configured to bedirected at least substantially in a vertical direction.

4. The method of embodiment 2, comprising the step of positioning theassembly in the ear canal of a person so that one or more of thedetector(s) and/or one or more of the emitter(s) is/are directed atleast substantially in a vertical direction.

5. The assembly according to embodiment 1 or 3, wherein:

-   -   one of the radiation detectors is positioned in or at the        housing and has a field of view defining a view axis,    -   one of the radiation emitters is positioned in or at the housing        and has an emission cone defining an emission axis.

6. The assembly of embodiment 5, wherein no overlap exists between thefield of view and the emission cone within a distance of 0 mm from thehousing.

7. The assembly of embodiment 6, wherein there is no overlap between thefield of view and the emission cone.

8. The assembly of any of embodiment 5-7, wherein the housing comprisesat least a first and a second non-overlapping surface parts directed indifferent directions, where:

-   -   the view axis of one of the detector(s) extends at an angle,        such as an angle in the interval of 30-160 degrees, such as        within the interval of 45-135 degrees, such as around 90        degrees, to the first surface part and    -   the emission axis of one of the emitter(s) extends at an angle,        such as an angle in the interval of 30-160 degrees, such as        within the interval of 30-160 degrees, such as within the        interval of 45-135, such as around 90 degrees to the second        surface part.

9. The assembly according to embodiment 8, wherein the housing has 6surface portions, pairwise at least substantially parallel, where eachpair of surface portions are at least substantially perpendicular to theother pairs of surface portions, the first surface portion being one ofthe 6 surface portions.

10. The assembly according to embodiment 9, wherein the second surfaceportion extends between at least two of the 6 surface portions and has anon-zero angle to each of the at least two of the 6 surface portions.

11. The method according to embodiment 2 or 4, wherein:

-   -   one of the radiation detectors detects radiation within a field        of view defining a view axis,    -   one of the radiation emitters emits radiation within an emission        cone defining an emission axis.

12. The method of embodiment 11, wherein there is no overlap between thefield of view and the emission cone.

13. The method of embodiment 12, wherein no overlap exists between thefield of view and the emission cone within a distance of 1 mm from thehousing.

14. The method of any of embodiment 11-13, wherein the housing comprisesat least a first and a second non-overlapping surface parts directed indifferent directions, where:

-   -   the view axis of one of the detector(s) extends at an angle,        such as an angle in the interval of 30-160 degrees, such as        within the interval of 45-135 degrees, such as around 90        degrees, to the first surface part and    -   the emission axis of one of the emitter(s) extends at an angle,        such as an angle in the interval of 30-160 degrees, such as        within the interval of 30-160 degrees, such as within the        interval of 45-135, such as around 90 degrees to the second        surface part.

15. The method according to embodiment 14, wherein the housing has 6surface portions, pairwise at least substantially parallel, where eachpair of surface portions are at least substantially perpendicular to theother pairs of surface portions, the first surface portion being one ofthe 6 surface portions.

16. The method according to embodiment 15, wherein the second surfaceportion extends between at least two of the 6 surface portions and has anon-zero angle to each of the at least two of the 6 surface portions.

17. An assembly of a receiver, a radiation emitter, a radiation detectorand an assembly housing, wherein:

-   -   the receiver has a receiver housing and is positioned inside the        assembly housing,    -   the radiation detector is positioned in the assembly housing and        has a reception direction along a first direction,    -   the radiation emitter is positioned in the assembly housing and        has an emission direction along a second direction, an angle        existing between the first and second directions,    -   one or more windows transparent to the radiation are provided in        the assembly housing for allowing radiation from the emitter to        exit the assembly housing and radiation from outside of the        assembly housing to reach the detector.

18. An assembly according to embodiment 17, wherein the assembly housingis arranged to have the radiation emitter or radiation emitterpositioned in ear canal to allow radiation to exit towards or enter fromthe direction towards the bottom of the ear canal.

19. The assembly according to any of embodiments 1, 3, 5-10 and 17-18wherein:

-   -   one of the radiation detectors is positioned in the housing and        has a field of view, and    -   one of the radiation emitters is positioned in the housing and        has an emission cone,

where a distance of at least 1 mm exists between the field of view andthe cone, within a distance of at least 0 mm from the housing.

20. The assembly of embodiment 19, wherein the housing is configured toengage an ear canal at a position comprised within the field of view orthe cone.

21. The assembly of embodiment 19 or 20, wherein the field of viewand/or cone is defined by a window and/or a lens at the outer surface ofthe housing.

22. A method according to any of embodiments 2, 4, and 11-16 wherein:

-   -   one of the radiation detectors receives radiation within a field        of view,    -   one of the radiation emitters emits radiation within an emission        cone, where a distance of at least 1 mm exists between the field        of view and the cone, within a distance of at least 1 mm from        the housing.

23. The method of embodiment 22, wherein the housing engages an earcanal at a position comprised within the field of view or the cone.

24. The method of embodiment 22 or 23, wherein the field of view and/orcone is defined by a window and/or a lens at the outer surface of thehousing.

25. The assembly according to any of embodiments 1, 3, 5-10, and 17-21,further comprising a receiver having a receiver housing, wherein atleast one of the one or more detectors and one or more emitters isattached to the receiver housing.

26. The assembly of embodiment 25, further comprising a first window orlens in the receiver housing and a second window or lens in either thehousing or an element attached to the housing, wherein an emitter ispositioned so as to emit radiation toward one of the first and secondwindow/lens and a detector is positioned so as to receive radiation viaanother of the first and second window/lens.

27. An assembly comprising a sensor and a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   the sensor comprises a radiation emitter and a radiation        detector,    -   the receiver housing at least one of the emitter and the        detector overlap at least partly when projected on to a first        plane, and    -   the receiver housing and the at least one of the emitter and the        detector overlap at least partly when projected on to a second        plane perpendicular to the first plane.

28. An assembly according to embodiment 27, further comprising anadditional element attached to the receiver, one of the emitter and thedetector being attached to the additional element.

29. An assembly according to embodiment 27 or 28, wherein:

-   -   the detector has a field of view having a first central axis,    -   the emitter defines an emission cone having a second central        axis, where a non-zero angle exists between the first and second        central axes.

30. An assembly according to any of embodiments 27-29, wherein thereceiver housing has a number of at least substantially plane surfaceparts, wherein the detector is provided in or at a first of the surfaceparts and the emitter is provided in or at a second of the surfaceparts.

31. The method according to any of embodiments 2, 4, 11-16, and 22-24further comprising a receiver having a receiver housing, wherein atleast one of the one or more detectors and one or more emitters isattached to the receiver housing.

32. The method of embodiment 31, wherein an emitter is positioned so asto emit radiation toward one of a first and a second window/lens and adetector is positioned so as to receive radiation via another of thefirst and second window/lens, the first window or lens being provided inor at the receiver housing and the second window or lens beingpositioned in or at either the housing or an element attached to thehousing,

33. A method of providing an assembly comprising a sensor and areceiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,            and    -   the sensor comprises a radiation emitter and a radiation        detector,    -   the method comprising providing the receiver and the sensor so        that:    -   the receiver housing at least one of the emitter and the        detector overlap at least partly when projected on to a first        plane, and    -   the receiver housing and the at least one of the emitter and the        detector overlap at least partly when projected on to a second        plane perpendicular to the first plane.

34. A method according to embodiment 33, further comprising anadditional element attached to the receiver, one of the emitter and thedetector being attached to the additional element.

35. A method according to embodiment 33 or 34, wherein:

-   -   the detector receives radiation in a field of view having a        first central axis,    -   the emitter outputs radiation in an emission cone having a        second central axis, where a non-zero angle exists between the        first and second central axes.

36. An assembly according to any of embodiments 33-35, wherein thereceiver housing has a number of at least substantially plane surfaceparts, wherein the detector is provided in or at a first of the surfaceparts and the emitter is provided in or at a second of the surfaceparts.

37. The assembly according to any of the preceding embodiments 1, 3,5-10, 17-21, and 25-30, wherein:

-   -   one of the radiation detectors is positioned in the housing and        has a field of view,    -   one of the radiation emitters is positioned in the housing and        has an emission cone,

the assembly further comprising a radiation blocking element provided inan overlap between the field of view and the cone.

38. The assembly according to embodiment 37, wherein the radiationblocking element engages the housing or is fixed to the housing andextends away from the housing.

39. The method according to any of the preceding embodiments 2, 4,11-16, 22-24, and 31-35 wherein:

-   -   one of the radiation detectors is positioned in the housing and        receives radiation within a field of view,    -   one of the radiation emitters is positioned in the housing and        emits radiation within an emission cone,

the method further comprising blocking radiation travelling in anoverlap between the field of view and the cone.

40. The method according to embodiment 39, wherein the blocking stepcomprises blocking the radiation with a radiation blocking elementengages the housing or is fixed to the housing and extends away from thehousing.

41. The assembly according to any of embodiments 1, 3, 5-10, 17-21,25-30, and 36-38, further comprising a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   one of the one or more detectors and one or more emitters        comprises a sensor housing,    -   the receiver housing and the sensor housing overlap at least        partly when projected on to a first plane, and    -   the receiver housing and sensor housing overlap at least partly        when projected on to a second plane perpendicular to the first        plane.

42. The assembly according to any of embodiments 1, 3, 5-10, 17-21,25-30, and 36-38, further comprising a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   one of the one or more detectors and one or more emitters        comprises a sensor housing being at least partially inside the        second chamber, and    -   the sensor housing or its portion inside the second chamber,        having a volume not exceeding 20% of a volume of the second        chamber.

43. An assembly comprising a receiver and a sensor, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   the sensor comprises a sensor housing being at least partially        inside the second chamber, and    -   the sensor housing or its portion inside the second chamber,        having a volume not exceeding 20% of a volume of the second        chamber.

44. An assembly comprising a sensor and a receiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   the sensor comprises a sensor housing,    -   the receiver housing and sensor housing overlap at least partly        when projected on to a first plane, and    -   the receiver housing and sensor housing overlap at least partly        when projected on to a second plane perpendicular to the first        plane.

45. An assembly according to embodiment 44, wherein the sensor housingis positioned at least partly inside the receiver housing.

46. An assembly according to embodiment 45, wherein the sensor housinghas an outer volume not exceeding 20% of an inner volume of the receiverhousing.

47. An assembly according to any of embodiments 43-46, wherein thesensor housing is positioned at least partly outside of the receiverhousing.

48. An assembly according to embodiment 47, wherein the sensor housingis attached to the receiver housing.

49. An assembly according to embodiment 47 or 48, further comprising oneor more conductors connected to the sensor housing and extending outsideof the sensor housing, at least a part of the conductor(s) extendinginside the receiver housing.

50. An assembly according to any of embodiments 43-49, wherein thereceiver diaphragm and sensor housing overlap at least partly whenprojected on to a first plane.

51. An assembly according to any of embodiments 43-50, wherein thereceiver housing and sensor housing, when projected on to a first plane,overlap an area of at least 10% of an area of the sensor housing in theprojection.

52. An assembly comprising a receiver and a sensor, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   the sensor comprises a radiation emitter and a radiation        detector, one of the radiation emitter and the radiation        detector being at least partially inside the second chamber.

53. An assembly according to embodiment 52, wherein the portion of theone of the emitter and the detector inside the second chamber has avolume not exceeding 20% of a volume of the second chamber.

54. The method according to any of embodiments 2, 4, 11-16, 22-24,31-35, 39, and 40 further comprising operating a receiver, comprising:

-   -   a receiver housing with a receiver housing wall part comprising        a sound output,    -   a receiver diaphragm defining, with an inner surface of the        receiver housing, a first chamber in the receiver housing,    -   the method comprising providing the housing, a sensor with a        sensor housing and the receiver so that:    -   the receiver housing and a sensor housing overlap at least        partly when projected on to a first plane, and    -   the receiver housing and sensor housing overlap at least partly        when projected on to a second plane perpendicular to the first        plane.

55. The method according to any of embodiments 2, 4, 11-16, 22-24,31-35, 39, and 40 further comprising operating a receiver comprising:

-   -   a receiver housing,    -   a receiver diaphragm defining, with an inner surface of the        receiver housing, a first chamber in the receiver housing having        a sound output, and a second chamber in the receiver housing,    -   the method comprising providing the housing, a sensor with a        sensor housing and the receiver so that:    -   one of the one or more detectors and one or more emitters        comprises a sensor housing being at least partially inside the        second chamber, and    -   the sensor housing or its portion inside the second chamber,        having a volume not exceeding 20% of a volume of the second        chamber.

56. A method of providing an assembly of a receiver and a sensor,wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing, and    -   the sensor comprises a sensor housing being at least partially        inside the second chamber,

the method comprising providing the sensor housing or its portion insidethe second chamber, having a volume not exceeding 20% of a volume of thesecond chamber.

57. A method of providing an assembly comprising a sensor and areceiver, wherein:

-   -   the receiver comprises:        -   a receiver housing with a receiver housing wall part            comprising a sound output,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing,    -   the sensor comprises a sensor housing,    -   the method comprising providing the receiver and sensor so that:    -   the receiver housing and sensor housing overlap at least partly        when projected on to a first plane, and    -   the receiver housing and sensor housing overlap at least partly        when projected on to a second plane perpendicular to the first        plane.

58. A method according to embodiment 75, wherein the sensor housing ispositioned at least partly inside the receiver housing.

59. A method according to embodiment 58, wherein the sensor housing hasan outer volume not exceeding 20% of an inner volume of the receiverhousing.

60. A method according to any of embodiments 55-59, wherein the sensorhousing is box-shaped and has 6 outer wall portions, where a wallportion with a largest surface area has a surface area not exceedingtwice a surface area of a wall portion having the smallest surface area.

61. A method according to any of embodiments 54-60, wherein the sensorhousing is positioned at least partly outside of the receiver housing.

62. A method according to embodiment 61, wherein the sensor housing isattached to the receiver housing.

63. A method according to embodiment 61 or 62, further comprising one ormore conductors connected to the sensor housing and extending outside ofthe sensor housing, at least a part of the conductor(s) extending insidethe receiver housing.

64. A method according to any of embodiments 54-63, wherein the receiverdiaphragm and sensor housing overlap at least partly when projected onto a first plane.

65. A method according to any of embodiments 54-64, wherein the receiverhousing and sensor housing, when projected on to a first plane, overlapan area of at least 10% of an area of the sensor housing in theprojection.

66. A method comprising providing an assembly of a receiver and asensor, wherein:

-   -   the receiver comprises:        -   a receiver housing,        -   a receiver diaphragm defining, with an inner surface of the            receiver housing, a first chamber in the receiver housing            having a sound output, and a second chamber in the receiver            housing,    -   the sensor comprises a radiation emitter and a radiation        detector, one of the radiation emitter and the radiation        detector being at least partially inside the second chamber.

67. A method according to embodiment 66, wherein the portion of the oneof the emitter and the detector inside the second chamber has a volumenot exceeding 20% of a volume of the second chamber.

68. The assembly according to any of embodiments 1, 3, 5-10, 17-21,25-30, 36-38, and 41-53 wherein:

-   -   the radiation detector(s) are positioned in or symmetrically on        either side of a plane extending through the housing and/or    -   the radiation emitter(s) is/are positioned in or symmetrically        on either side of the plane.

69. The assembly according to embodiment 68, wherein the housing isconfigured to be positioned so that the plane is at least substantiallyvertical.

70. The assembly according to embodiment 68 or 69, wherein at least onedetector is positioned to receive radiation travelling in the plane.

71. The method according to any of embodiments 2, 4, 11-16, 22-24,31-35, 39, 40, and 54-67 comprising:

-   -   positioning the radiation detector(s) in or symmetrically on        either side of a plane extending through the housing and/or    -   positioning the radiation emitter(s) in or symmetrically on        either side of the plane.

72. The method according to embodiment 71, wherein the housing ispositioned in an ear canal so that the plane is at least substantiallyvertical.

73. The method according to embodiment 71 or 72, wherein at least onedetector is positioned to receive radiation travelling in the plane.

74. The method according to any of embodiments 71-73, comprisingproviding two of the assemblies and providing one in a left ear canal ofa person and the other in the right ear canal of the person.

75. The assembly according to any of embodiments 1, 3, 5-10, 17-21,25-30, 36-38, 41-53, 68-70, wherein the housing is oblong with a firstend portion and a second, opposite end portion, the housing comprising asound outlet in or at the first end portion, where a majority of theradiation emitter(s) and a majority of the radiation detector(s) is/arepositioned closer to the first end portion than the second end portion.

76. The assembly according to embodiment 75, the assembly furthercomprising a receiver positioned in the housing, where a majority of theradiation emitters and the radiation detectors are positioned, in aprojection on to a longitudinal axis of the housing, closer to the firstend portion than a centre of the receiver.

77. The method according to any of embodiments 2, 4, 11-16, 22-24,31-35, 39, 40, 54-67, and 71-74, wherein the housing is oblong with afirst end portion and a second, opposite end portion, the housingcomprising a sound outlet in or at the first end portion, the methodcomprising positioning a majority of the radiation emitter(s) and amajority of the radiation detector(s) closer to the first end portionthan the second end portion.

78. The method according to embodiment 77, further comprisingpositioning a receiver in the housing, where the step of positioning themajority of the radiation detector(s) and the majority of the radiationemitter(s) comprises positioning a majority of the radiation emittersand the radiation detectors are positioned, in a projection on to alongitudinal axis of the housing, closer to the first end portion than acentre of the receiver.

1. An assembly of at least one radiation detector, at least oneradiation emitter and a housing configured to be positioned inside theear canal of a person or animal, the detector(s) and emitter(s) beingprovided in or on the housing, the emitter(s) being configured to emitradiation away from the housing and the detector(s) being configured toreceive radiation directed toward the housing.
 2. The assembly accordingto claim 1, wherein one or more of the detector(s) and/or one or more ofthe emitter(s) is/are configured to be directed at least substantiallyin a vertical direction.
 3. The assembly according to claim 1, wherein:one of the radiation detectors is positioned in or at the housing andhas a field of view defining a view axis, one of the radiation emittersis positioned in or at the housing and has an emission cone defining anemission axis, wherein there is no overlap between the field of view andthe emission cone.
 4. The assembly according to claim 1, wherein: one ofthe radiation detectors is positioned in the housing and has a field ofview, and one of the radiation emitters is positioned in the housing andhas an emission cone, where a distance of at least 0 mm exists betweenthe field of view and the cone, within a distance of at least 1 mm fromthe housing.
 5. The assembly according to claim 1, further comprising areceiver having a receiver housing, wherein at least one of the one ormore detectors and one or more emitters is attached to the receiverhousing.
 6. The assembly according to claim 1, wherein: one of theradiation detectors is positioned in the housing and has a field ofview, one of the radiation emitters is positioned in the housing and hasan emission cone, the assembly further comprising a radiation blockingelement provided in an overlap between the field of view and the cone.7. The assembly according to claim 1, further comprising a receiver,wherein: the receiver comprises: a receiver housing with a receiverhousing wall part comprising a sound output, a receiver diaphragmdefining, with an inner surface of the receiver housing, a first chamberin the receiver housing, one of the one or more detectors and one ormore emitters comprises a sensor housing, the receiver housing and thesensor housing overlap at least partly when projected on to a firstplane, and the receiver housing and sensor housing overlap at leastpartly when projected on to a second plane perpendicular to the firstplane.
 8. The assembly according to claim 1, further comprising areceiver, wherein: the receiver comprises: a receiver housing, areceiver diaphragm defining, with an inner surface of the receiverhousing, a first chamber in the receiver housing having a sound output,and a second chamber in the receiver housing, one of the one or moredetectors and one or more emitters comprises a sensor housing being atleast partially inside the second chamber, and the sensor housing or itsportion inside the second chamber, having a volume not exceeding 20% ofa volume of the second chamber.
 9. The assembly according to claim 1,wherein: the radiation detector(s) are positioned in or symmetrically oneither side of a plane extending through the housing and/or theradiation emitter(s) is/are positioned in or symmetrically on eitherside of the plane.
 10. The assembly according to claim 1, wherein thehousing is oblong with a first end portion and a second, opposite endportion, the housing comprising a sound outlet in or at the first endportion, where a majority of the radiation emitter(s) and a majority ofthe radiation detector(s) is/are positioned closer to the first endportion than the second end portion.
 11. A method of operating anassembly of claim 1 being adapted for a universal fitting in either aleft or a right ear canal of a person, the method comprising the stepsof: providing the assembly in one of the left and the right ear canal,feeding information to the assembly as to which of the left and rightear canal the assembly was provided in, operating the assembly inaccordance with the information.
 12. A method of operating an assemblyof claim 1, the method comprising the steps of: determining relativemovement between an ear canal and the assembly housing and operating inaccordance with the relative movement determined; generating a controlsignal to adjust the operation of the assembly.